content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * ---------------------
   * EntityCollection.java
   * ---------------------
   * (C) Copyright 2002-2008, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 23-May-2002 : Version 1 (DG);
   * 25-Jun-2002 : Removed unnecessary import (DG);
   * 26-Jun-2002 : Added iterator() method (DG);
   * 03-Oct-2002 : Fixed errors reported by Checkstyle (DG);
   * 30-Jan-2004 : Added a method to add a collection of entities.
   * 11-Jan-2005 : Removed deprecated code in preparation for the 1.0.0
   *               release (DG);
   * 18-Jan-2005 : Added getEntity() and getEntityCount() methods (DG);
   *
   */
  
  package org.jfree.chart.entity;
  
  import java.util.Collection;
  import java.util.Iterator;
  
  /**
   * This interface defines the methods used to access an ordered list of
   * {@link ChartEntity} objects.
   */
  public interface EntityCollection extends Iterable<ChartEntity> {
  
      /**
       * Clears all entities.
       */
      public void clear();
  
      /**
       * Adds an entity to the collection.
       *
       * @param entity  the entity (<code>null</code> not permitted).
       */
      public void add(ChartEntity entity);
  
      /**
       * Adds the entities from another collection to this collection.
       *
       * @param collection  the other collection.
       */
      public void addAll(EntityCollection collection);
  
      /**
       * Returns an entity whose area contains the specified point.
       *
       * @param x  the x coordinate.
       * @param y  the y coordinate.
       *
       * @return The entity.
       */
      public ChartEntity getEntity(double x, double y);
  
      /**
       * Returns an entity from the collection.
       *
       * @param index  the index (zero-based).
       *
       * @return An entity.
       */
      public ChartEntity getEntity(int index);
  
      /**
       * Returns the entity count.
       *
       * @return The entity count.
       */
      public int getEntityCount();
  
      /**
       * Returns the entities in an unmodifiable collection.
       *
       * @return The entities.
       */
      public Collection<ChartEntity> getEntities();
  
      /**
       * Returns an iterator for the entities in the collection.
       *
       * @return An iterator.
       */
      public Iterator<ChartEntity> iterator();
  
  }
  